双生子儿童口腔微生物群组结构分析

目的 通过聚合酶链反应-变性梯度凝胶电泳（PCR-DGGE）分析双生子儿童中同卵双生子和异卵双生子口腔微生物群组结构的差异。方法 选取双生子儿童20对，其中同卵双生子10对，异卵双生子10对；乳牙列10对，混合牙列10对；有龋者17人，无龋者23人。采集唾液样本后，提取细菌DNA，经通用引物扩增16s rRNA基因和PCR-DGGE分析后，计算PCR-DGGE条带数及多样性指数。结果 同卵双生子与异卵双生子均表现出明显的聚类分布，但同卵双生子与异卵双生子之间无统计学差异（P>0.05）。乳牙列组中，有龋儿童的PCR-DGGE条带数（11.00±1.56）及多样性指数（1.05±0.36）低于无龋儿童（14.00±2.74，1.44±0.37），两者间均具有统计学差异（P<0.05）。混合牙列组中，有龋儿童的PCR-DGGE条带数（11.88±4.05）及多样性指数（1.18±0.36）低于无龋儿童（14.31±5.71，1.28± 0.47），但两者间均无统计学差异（P>0.05）。结论 亲缘之间口腔微生物组群结构更为相似，环境的影响可能大于遗传的影响。有龋儿童的微生物种类较无龋儿童有所减少。

Analysis of the oral microbiota in twin children

Objective   To analyze the differences between the oral microbiota of monozygotic and dizygotic twins by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Methods   A total of 20 pairs of twin children were included in this study, in which 10 pairs were monozygotic (MZ) twins, and 10 pairs were dizygotic (DZ) twins. Of the 20 pairs, 10 pairs of twins had primary dentition, and 10 pairs had mixed dentition; 17 children had caries, and 23 children had no caries. Genomic DNA was extracted from saliva samples. The 16s rRNA was amplified and analyzed by PCR-DGGE. The PCR-DGGE band number and Shannon index were calculated. Results   Cluster analysis showed high similarity in the oral bacterial community seen in co-twins. However, no significant difference was seen between MZ and DZ twins. In the primary dentition, the PCR-DGGE band number and Shannon index of children with caries (11.00±1.56, 1.05±0.36) were lower than those of children without caries (14.00±2.74, 1.44±0.37) (P<0.05). In mixed dentition, the PCR-DGGE band number and Shannon index of children with caries (11.88±4.05, 1.18±0.36) were lower than those of children without caries (14.31±5.71, 1.28±0.47), but the differences were not statistically significant (P>0.05). Conclusion   Environmental factors may have a stronger effect on the constitution of oral microbiota in children compared with genetic factors. Children without caries may have a richer microbial diversity compared with children with caries.